200,000 Miles and Yet Not in First Class?

What would you do if you spent 200,000 miles for two people to be in the first class cabin on a domestic flight within the United States, only to be involuntarily downgraded to coach class, as is what allegedly happened to FlyerTalk member b-squared21?

Before arrriving at a judgment and a conclusion, consider the following:

They arrived at the gate 5 minutes before departure.

Their flight to connect to the flight on which they were denied the opportunity to sit in the first class cabin arrived 40 minutes late, shortening their connection time in Houston.

They used 200,000 Northwest Airlines WorldPerks miles to pay for the award ticket for their flight.